Slip form for casting concrete



June 23, 1970 H. YODER SLIP FORM FOR CASTING CONCRETE Filed- Jan. 22, 1968 4 Sheets-Sheet 1 FIG-2 June 23, 1970 H. H. YODER SLIP FORM FOR CASTING CONCRETE Filed Jan. 22. 1968 4 Sheets-Sheet 3 FIG 6 m Rw OY T. NH Ev VE NV m H June 23, 1970 H. H. YODER SLIP FORM FOR CASTING CQNCRETE 4 Sheets-Sheet 5 Filed Jan. 22, 1968 INVENTOR HARVEY H. YODER BY I . June 1970 H. H. YODER 3,516,129

SLIP FORM FOR CASTING CONCRETE 7 Filed Jan. 22, 1968 I 1r 4 Sheets-Sheet 4.

FIG-9 INVENTOR. HHRVEY H. YODER' MM W71 United States Patent 3,516,129 SLIP FORM FOR CASTING CONCRETE Harvey H. Yoder, Rte. 2, West Liberty, Ohio 43357 Filed Jan. 22, 1968, Ser. No. 699,474 Int. Cl. E04h 7/26; E03b 11/00 US. Cl. 25-124 15 Claims ABSTRACT OF THE DISCLOSURE This invention relates to concrete forms and is particularly concerned with slip forms.

Slip molding forms for use in erecting concrete structures are, of course, known and are forms so constructed and arranged that they can be moved more or less continuously in the vertical direction at such a speed that the concrete emerging at the bottom of the form is selfsupporting and, if desired, can be finished while new concrete is being poured into the top of the form. By the use of slip forms, monolithic structures can be erected which are free of joints and which, due to the continued movement of the slip forms during the erection process, can be erected relatively quickly.

While slip forms, as mentioned, are known, it has always been a problem to insure that all parts of the form will move at the same rate of speed and it has, furthermore, always been a problem conveniently to arrange the form structure for use by workmen in the operation of adding reinforcing iron to the structure as it is being poured, pouring the concrete, and like operations.

Having the foregoing in mind, a particular object of the present invention is the provision of a slip form for use in the casting of concrete structures which is convenient to use.

Another object of this invention is the provision of a slip form for use in the erection of concrete structures in which all parts of the form are constrained to move at the same rate of speed as the form moves upwardly.

A still further object of the present invention is the provision of a slip form for use in the erection of cylindrical structures which produces superior end results over what can be obtained from the use of conventional slip forms.

Still another object of the present invention is the provision of a slip form, especially for cylindrical structures, which is convenient to set up and dismantle.

The foregoing objects as well as other objects and advantages of the present invention will become more apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:

FIG. 1 is a perspective view showing a cylindrical structure in the process of being erected by the use of a slip form according to the present invention;

FIG. 2 is a plan view looking down on top of the structure of FIG. 1;

FIG. 3 is a vertical sectional view indicated by line III-III on FIG. 2;

FIG. 4 is a view drawn at enlarged scale and showing 3,516,129 Patented June 23, 1970 ice a main lift yoke and a winch structure therefor and is indicated by line IV-IV on FIG. 2;

FIG. 5 is a view drawn at enlarged scale, similar to FIG. 4, and showing one of the intermediate yokes and is indicated by line VV on FIG. 2;

FIG. 6 is a schematic representation of float controlled switches forming a part of an electrical control circuit for controlling the Winch motors that moves the form vertically;

FIG. 7 is a plan sectional view showing details in respect of the form structure;

FIG. 8 is a vertical sectional view taken on line VIII VIII of FIG. 2; and

FIG. 9 is a schematic representation of an electric control circuit.

Referring to the drawings somewhat more in detail, in FIG. 1, 10 represents a cylindrical structure such as a silo which is being erected by the use of the slip form according to the present invention and which is generally indicated at 12. As is known, the structure is erected by positioning the slip form at its lowest position and placing concrete therein and thereafter, when the concrete has set sufficient to make it self-supporting, the form is set into motion in the upward direction and moves at such a rate, slipping over the concrete therein, that the concrete as it becomes exposed at the bottom of the form is self-supporting and is in such condition that it can be finished as by trowelling, if a finishing operation is to be carried out.

The form, once set in motion, may be kept in motion until the structure is completed, or it may be moved intermittently if necessary or desirable.

In the silo structure shown, a base member 14 is first formed and which may take the form of a concrete slab underlying the silo structure, or it may be in the form of a cylindrical footer. In any case, the number 14 forms the lower closure for the slip form when the concrete pouring operation is initiated.

The slip molding form, as will be seen in FIGS. 2, 3 and 4, comprises an outer cylindrical form part 16 and an inner cylindrical form part 18 radially spaced from outer part 16 a distance substantially equal to the thickness of the wall to be poured. Each of the inner and outer forms may be made up as shown in FIG. 7 of sections or segments, each consisting of curved metal plates 20 having angles 22 fixed to the edges thereof. The adjacent sections or segments may be bolted together by bolts 24 passing through adjacent angles 22, or the angles may merely carry cooperating pin and hole means for aligning the form segments or sections and supporting banding applied to the forms. With the outer form the concave side of the form is unobstructed, whereas with the inner form, the convex side of the form is unobstructed.

At spaced points about the outer form 16, as will be seen in FIG. 5, and toward the top of the outer form there are secured the outwardly extending members 26 spaced in the vertical direction so as to receive therebetween a curved channel member 28. Members 26 are U- shaped (FIG. 7), or are apertured for receiving drift pins 30 so that when the curved channels are put in place, the drift pins can be driven in place and the plates of the outer form and the curved support channels 28 will be fixedly interconnected. Channels 28 are formed in sections and are adapted for having their ends interconnected (FIG. 7) so as to form a supporting ring completely surrounding the upper portion of outer form 16. Toward the bottom of the outer form there may be provided a banding strap 32 which is passed around the form and the ends thereof connected so as to support the lower part of the outer form.

At spaced points about the inner form near the top and near the bottom there is also provided the members 26 which receive therebetween the curved channels 28 which, as in connection with the channels 28 pertaining to the outer form, are secured together in end to end relation thereby to provide an inner support for the inner form 18.

The inner form at spaced points thereabout, as shown in FIG. 8, also has the vertically extending plates 34 fixed thereto by hooks 35 at the bottom and bolted brackets 37 at the top. Plates 34 are availed of for supporting the radial beams 36. The radial beams 36 at their outer ends are secured to plates 34 as by bolts 40 whereas at their inner ends they are secured as by bolts 42 to a central structure 44 that includes a socket 46 from which there extends upwardly a central post or mast 48. The radial beams 36 are arranged for supporting flooring elements 38, plywood, for example, which form a work platform or floor disposed at about the level of the top of the inner form 18. The central structure 44 may advantageously be braced by the angular braces 50 extending downwardly from the top of the central structure to near the lower part of the inner form 18. As will be seen in FIG. 2 there are four of the radial beams 36 and the quadrants left therebetween may be filled in with other support members 52 so as to provide a good support for the floor resting on the beam structure.

The structure described at this point comprises a cylindrical outer form made up of sections or segments which can be placed together or taken apart and which are firmly supported so as to resist internal pressures. The internal form is similarly made up of sections or segments which can be assembled or disassembled and which are also firmly supported against internal pressures within the form. Both the inner and outer forms can be considered relatively rigid structures but it will be evident that in erecting a cylindrical structure of any substantial size, a silo, for example, the form parts would be of such size that there would be considerable flexibility therein so that they could twist relative to each other. Furthermore, the forms could be cocked bodily relative to the vertical as well as become twisted.

The inner and outer forms according to the present invention are interconnected by inverted U-shaped yoke members, some of which are connecting intermediate yokes and others of which are main lifting yokes to which power is supplied for moving the assembled form made up of the inner and outer form parts in the vertical direction. The intermediate yokes and the main lifting yokes may be distributed about the form structure at any desired intervals, the intervals being determined by the size of the structure.

An intermediate yoke assembly is shown in FIG. 5, where it will be seen to comprise an inverted U-shaped tubular member 60 having an inner leg 62 that extends downwardly inside the inner form and an outer leg 64 that extends downwardly outside the outer form. The legs 62 and 64 are arranged to lie adjacent channel members 28 and include hook-like parts adapted for engaging beneath the channel members. In respect of outer leg 64, a hook-shaped member 66 is adapted for being inserted in the lower end of leg 64 and retained therein by a pin 68. Hook-shaped member 66 is adapted for engaging beneath the outer ring like channel member 28 so as to engage outer form 16 in supporting relation thereto. The inner leg 62 has a similar hook-like member 66 adapted for being received in the bottom end thereof and to be retained therein by a pin 68 and adapted for engaging beneath the lower one of ring-like supporting channel members 28 pertaining to the inner form. Leg 62 may have a further pin 70 which can be passed therethrough near the upper end of inner form 18 for engagement with a suitable aperture therein for retaining the intermediate yokes in an upright position on the form structure. Each intermediate yoke has a rod-like part 72 extending up wardly therefrom above the outer leg 64 so that the inter mediate yokes together with the main yokes, to be described hereinafter, form a supporting table on which reinforcing the iron can be supported.

Turning now to FIG. 4, the main lifting yokes are illustrated therein. Each main lifting yoke, generally identified at 74, is also an inverted U-shaped member and comprises an inner leg 76 and an outer leg 78 each of which extends downwardly adjacent the respective ringlike supporting channel members .28 of the respective forms. Each leg 76, 78 receives a hook-like member '80 in the lower end which engages beneath the respective channel member 28. Pins 82 retain the main yokes 74 in assembled relation with their respective forms. The aforementioned yokes 60, 74 fix the inner and outer form parts relative to each other and insure that both form parts will move together. As mentioned before, the number of main yokes 74 and intermediate yokes 60 required depend on the size of the structure. For the purpose of simplification there have been shown in the drawings four intermediate yokes and four main yokes, but it will be understood that there could be as many as each of the yoke structures as was necessary in order to support the forms properly and to supply power thereto for lifting the forms during the casting operation.

As will be seen in FIG. 4, each main yoke 74 has an upstanding post 84 at the outer edge corresponding to post 72 of intermediate yokes 60 to form the table on which reinforcing iron can be supported. Each main yoke, furthermore, toward the inside has an upstanding plate member 86 apertured at 88 for receiving a lifting element; as shown, the hook on the frame of a sheave so that the forms can be raised or lowered. Plate 86 has an inclined edge at 90 so that reinforcing iron placed on top of the yokes will tend to be confined to the outer portion thereof.

Adjacent each of the main yokes, and stationarily supported inside the inner form, either on the ground or on the base member for the structure, is a vertical post 100. Each vertical post has slidably mounted thereon an elongated tubular element 102 forming a part of the pertaining lift winch assembly. Post 100 may be in the form of a pipe and have holes 104 distributed therealong. Elements 102 may be held stationary by being pinned to the posts 100, although when the form parts are being moved, the elements 102 are free to slide on their respective posts.

Tubular element 102 has a hook-like structure 106 fixed to its lower end which engages beneath the lower ring-like supporting channel member 28 of the inner form. At their upper ends tubular members 102 are fixed to the lower ends of the legs 76 of the adjacent main yokes 74 and also carry a powered winch structure generally indicated at 108. Each winch structure comprises the winch drum member 110 to which is connected a cable 112 and also comprises a drive motor 114 which is connected to winch drum 110 by the belt and pulley means 116.

Located above the forms at a suitable position along each post 100 is a sheave assembly comprising a housing slidable on the respective post and held in place on the respective post by a bolt or pin 122 extending through one of the holes 104 in the post, and sheaves 124, 126 in the frame.

Further, a single sheave 128 and a supporting frame therefor is provided for each main lifting yoke 74. The frame of each sheave 128 comprises hook 130 which engages the hole 88 in plate 86 of the pertaining main lift yoke. The cable 112 pertaining to each winch drum 110 is entrained over one of pulleys 124, 126 and then about pulley 128 and then back over the other of pulleys 124, 126 and then leads downwardly to the form structure, to an anchor place 132, which may be any suitable point, such as a stationary point or, as shown, a point on the inner form.

It will be evident that, upon the energization of a drive motor 114, the cable pertaining thereto will be reeled in on the pertaining winch drum and an upward force will be exerted on each main lift yoke and on the tubular element 102 pertaining thereto. This will cause upward movement of the interconnected inner and outer form parts as a unit together with the pertaining tubular ele ment 102 and the winch structure supported thereon. Inasmuch as the aforementioned working platform structure, consisting of beams 36 and intermediate members 52 and the floor 38 supported thereon, is connected to the inner form part, it also moves upwardly together with the form structure.

When the form parts are moved to such level that a frame 120 must be elevated, the cable pertaining thereto is made slack and the member is moved to a higher location on the respective support post, and pinned in place. The pertaining cable is then again made taut. The frames 120 are, of course, moved one at a time.

Since it is of advantage to reinforce concrete structures, the outer form part may carry guide elements 150 through which vertically extending reinforcing rods 152 can slidably extend. As the form parts move upwardly, the reinforcing rods extending in the vertical direction are guided and supported by the guides 150 so that they occupy the proper position within the body of the concrete being poured.

As mentioned before, the upper ends of the yokes can form a table for supporting arcuate reinforcing rods indicated at 154 which can be connected with the vertical rods 152 at vertically spaced points therealong as by wiring the rods 154 to the rods 152.

As will be seen in FIGS. 3, 4 and 5, the outer form part is higher than the inner form part and this makes it a simple matter to pour concrete into the space between the inner and outer form parts as by availing of a wheelbarrow 156. Automatic distributor means for supplying concrete to the space between the inner and outer form parts could also be employed.

It is found convenient, however, to fix a beam 160 to the center column or mast 162 and to have the beam extend laterally beyond one side of the outer form part. Beam 160 is supported by a framework 164 which is fixed to the inner form part structure or to some part that is attached thereto and moves therewith. Moveably carried on the beam 160 is a carriage 166 that has a hook structure 168 connected thereto and also has a sheave 170 fixed thereto over which passes a cable 172. Cable 172 is adapted for lifting concrete container 174 to such a position that the trunnions 176 on the carrier can be engaged by the hook 168.

When the carrier is engaged by the hook 168, carriage 166 is moved inwardly and a workman standing on platform 178 can tilt the carrier 174 and pour the contents thereof into a receiver or hopper 180. Receiver or hopper 180, as will be seen in FIG. 3 comprises a door 182 which can be opened to permit the concrete therein to pour into wheelbarrow 156 or into any other desired distributor for the concrete. The mast 162 and all the parts connected therewith move upwardly with the form parts so that no adjustment thereof is required at any time.

The center mast can also be availed of for supporting a cord holder 190 which guides electric cable 192 to the mast so that it can be brought down the mast to a central control station carried by the mast as indicated at 194.

The mast is preferably provided with a brace member 196 to assit in sustaining the weight of the load imposed thereon. The receiver or hopper 180 is stationary relative to rail 160 and is connected at its opposite sides to the support posts that support the rail 160 and may be braced in any other suitable manner as, for example, as by brace rods 198 extending from the front end of the hopper upwardly to and connected with rail 160.

In the drawings, as will be seen in FIG. 2, four lift winch arrangements are shown connected with the forms for elevating them during the casting operation. It will be understood, however, that as many of the lift winch arrangements could be employed in distributed relation as might be desired or necessary. For the sake of simplicity, only four have been illustrated in the drawings.

The several winch motors are controlled in accordance with the electric circuit shown in FIG. 9 which incorporates therein the float switch arrangement of FIG. 6.

Referring first to FIG. 6 it will be seen that there is a respective switch S1, S2, S3, S4 for each winch motor. Each switch has a switch blade 200 connected with a float element 202 that floats on a body of liquid 204. All of the bodies of liquid are interconnected by flexible hoses 206 which is provided with means at 208 for filling the system with liquid to the proper level. The float switches are normally closed but if one motor drives its winch at a higher speed than the other motors so as to elevate the adjacent region of the form parts above the remainder of the form parts, the switch pertaining thereto will open because the liquid level pertaining to the said switch will drop relative to the switch structure. The pertaining motor will thus be deenergized and will remain deenergized until the assembled form is again level.

Turning now to FIG. 9, which shows a representative electric control circuit, the circuit is connected between power lines L1 and L2. A main switch 210 is provided which can be opened to deenergize the entire circuit. When switch 210 is closed, blade 212 of a selector switch is energized. Blade 212 can be closed on a contact 214 which will supply current through a timer arrangement 216 to the coil of a relay R1. The opening and closing of relay R1 is under the control of the timer, which determines the rate of the closings of relay R1 and the length of time it remains closed. Relay R1 has a plurality of blades connected in circuit with the winch motors M1, M2, M3 and M4, and when relay R1 is closed, the motors run in a direction to elevate the forms.

It will be understood that the timer unit 216 determines the rate of movement of the forms upwardly so that the proper speed thereof is obtained. Other speed control means for the winch motors is possible.

When blade 212 is closed on a contact 216, a switch blade 218 is energized. When blade 218 is closed on contact 220, relay R1 is energized and all of the motors, M1, M2, M3 and M4, run in a direction to lift the form but are not controlled as to speed and are free of the control of the float switches. When blade 218 is closed on a contact 222 the coil of relay R2 is energized and this closes the blades pertaining to relay R2 that energizes all of motors M1, M2, M3 and M4 to move the forms downwardly.

When blade 212 is closed on a contact 224 the switch blades SMl, SM2, SM3 and SM4 are energized and each of these blades is selectively moveable to control its pertaining motor so as to drive the winch pertaining thereto in either upward or downward direction. Switches SMl, SM2, SM3 and SM4 are availed of when the sheaves 124, 126 pertaining to the respective lift winch are to be moved upwardly and then readjusted.

It will be noted in the electric circuit that no possibility exists for improper energization of any of the motors and each thereof can be energized in only one manner at a time.

From the foregoing, it will be seen that the present invention provides a relatively simple slip form arrangement which can quickly be erected and quickly knocked down and which will operate to move upwardly in a substantially level position at all times with means being provided for adjustment and correction of the mechanism at any time necessary.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions; and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed is:

1. A slip form structure comprising: spaced form parts defining therebetween a space for receiving concrete, inverted U-shaped yokes interconnecting said form parts,

stationary vertical posts in spaced relation adjacent one of said form parts, a frame slidable on each post and connected to a respective yoke, a rotatable winch in each frame, a pulley housing on each post above the form parts having a pair of pulleys therein, a further pulley on top of each yoke which is connected to a said frame, a cable leading from each winch over one of the pertaining pair of pulleys and then over the pertaining further pulley and then back over the other of the said pair of pulleys and then to an anchor point, an electric drive motor on each frame connected to the respective winch, energizing circuit means for said motors, a control switch in each motor circuit having a body of liquid therein and means sensitive to lowering of the level of said body of liquid beyond a predetermined amount in the respective switch for opening the switch, and conduit means hydraulically interconnecting all of said bodies of liquid.

2. A slip form structure according to claim 1 in which each said motor is reversible and said energizing means includes first means operable for energizing said motors via the respective control switches to run in one direction so as to move the form parts vertically upwardly and second means operable for energizing said motors to run in the opposite direction so as to lower said form parts.

3. A slip form structure according to claim 2 in which said energizing circuit means includes third means operable for energizing said motors to run in said one direction and bypassing said control switches.

4. A slip form structure according to claim 2 in which said energizing circuit means includes fourth means operable for independently and selectively energizing any of said motors to run in either direction.

5. A slip form structure according to claim 1 in which said yokes comprise main lifting yokes attached to said frames and intermediate yokes disposed between said main yokes.

6. A slip form structure according to claim 5 in which said yokes are detachably connected to said form parts.

7. A slip form structure according to claim 6 in which platform means is included connected to one of said form parts to move therewith and forming a work floor giving access to the space between said form parts.

8. A slip form structure according to claim 1 in which each said pulley housing is adjustable along its respective post.

9. A slip form structure according to claim 8 in which said form parts are circular and concentric and said posts are inside the inner one of said form parts and said platform is carried by said inner form part near the top thereof and forms a substantially complete floor extending to the lateral limits of the inner form part in all directions.

10. A slip form structure according to claim 9 in which the outer'form part extends upwardly to a level higher than the inner form part.

11. A slip form structure according to claim 10 in which said outer form part includes circumferentially spaced guides for slidably engaging and locating vertical reinforcing rods which extend into the space between the form parts.

12. A slip form structure according to claim 11 in which said yokes are horizontal on top and together form table means for supporting reinforcing rods to be arranged horizontally in the space between said form parts.

13. A slip form structure according to claim 10 in which said platform supports a mast, a rail connected at one end to the mast and extending horizontally from said mast to beyond the outer form part, a carriage moveable along the rail, and means on the carriage for lifting containers of concrete from ground level up to a level to be received on said platform.

14. A slip form structure according to claim 13 in which said platform includes a hopper to receive the concrete, said hopper including means to dispense the concrete to a distributor.

15. A slip form structure according to claim 1 in which said energizing circuit means includes means to control at least the vertically upward rate of movement of the form structure by said motors.

References Cited UNITED STATES PATENTS 1,165,586 12/1915 Fraser et al. 25124 1,438,784 12/1922 Polk 25-124 2,580,536 1/1952 Fiorenzi 24920 2,596,854 5/1952 Jack 25124 2,621,389 12/1952 Von Heidenstam 25-124 2,851,759 9/1958 Berntsen.

3,453,707 7/ 1969 Johansson.

J. SPENCER OVERHOLSER, Primary Examiner B. D. TOBOR, Assistant Examiner US. Cl. X.R. 

